*69Opinion
WOODS, P. J.his is an appeal from a judgment of the Ventura County Superior <ourt granting a writ of prohibition. The writ re? strains all proceeditgs by the municipal court in the case of People of the State of Califoiia v. Juan M. Banales et al., on the grounds that the Agricultural Latjr Relations Act preempts the jurisdiction of the municipal court to har criminal prosecution of respondents herein.
The superior court’ decision to issue the writ was based solely on pleadings and documetary exhibits; no testimony was offered. Since the factual matters in his cause were submitted on three declarations under penalty of perju?, our summary of the facts is likewise based thereon, together with tk reasonable inferences drawn therefrom in the light most favorable to ispondent.
On February 17, 1977¿respondents, Juan' M. Banales and 33 others, were farm workers, emplyees of Sun Harvest, Inc. and Growers Exchange, Inc., involved in ílabor dispute with Growers Exchange, Inc., an agricultural employer. )n that date, they were picketing outside a celery field in Oxnard. Eigt workers were picking celery on the employer’s premises. Banales md the others (hereinafter referred to as respondents) entered into te fields to communicate with the “strike breaking farm workers.”
Les Diffenbaugh, a crew suervisor for the employer, “rushed to meet the picketers, as the other secrity man ushered the workers into an armored labor bus away from te picketers.” Diffenbaugh informed the men (through a Spanish interpeter) that they were being arrested for violating section 602, subdivision (j) of the Penal Code, for interfering with the lawful activities of thejompany. The respondents were subsequently charged with criminal trspass, a misdemeanor. Their motion in the municipal court to dismiss th charges, on the grounds that jurisdiction over their conduct was vestei exclusively in the Agricultural Labor Relations Board (hereinafter ARB), was denied. Respondents then brought a writ petition to the suprior court, and a writ of prohibition was granted, from which this apptfi is taken.
At issue is the jurisdiction of a s\te court over conduct which is arguably protected by the Agricultura Labor Relations Act (hereinafter ALRA). We have concluded that thtsuperior court properly prohibited *70further proceedings by the municipal court and tl-refore affirm the judgment appealed from.
ALRA (Lab. Code, § 1140 et seq.) is derived fr<n the National Labor Relations Act (NLRA). (Belridge Farms v. Agricultural Labor Relations Bd. (1978) 21 Cal.3d 551, 556 [147 Cal.Rptr. 165, 580 P.2d 665].) It has long been recognized that NLRA ve¡ed exclusive jurisdiction in the federal National Labor Relations Boar “whenever it is clear or may fairly be assumed” that activities complined of are protected by the act. Under those circumstances, state <>urt jurisdiction must yield to the federal board. (San Diego Unions v. Garmon (1959) 359 U.S. 236, 245 [3 L.Ed.2d 775, 783, 79 S.Ct. 73].) When the ALRA was enacted by the California Legislature in 1*75, it included two provisions, similar if not identical to the langiige of the federal act, evincing a clear legislative intent that the AlRB shall have exclusive jurisdiction over conduct covered by the act. Labor Code section 1160.9 provides: “The procedures set forth in this chpter shall be the exclusive method of redressing unfair labor practices.’
Also pertinent to the issue presented hre is Labor Code section 1166.3, subdivision (b), which provides: “If ny other act of the Legislature shall conflict with the provisions o' this part, this part shall prevail.”
Not only does the ALRB have exclsive jurisdiction over conduct protected by the act, but the initial detemination as to whether particular conduct is so protected must be rade by the board and not the court. Numerous federal decisions firstrecognized the importance of such a rule. (See, e.g., San Diego Union v. Garmon, supra, 359 U.S. at p. 245 [3 L.Ed.2d at p. 783]; Garner v. Teamster’s Union (1953) 346 U.S. 485, 490 [98 L.Ed. 228, 239, 74 S.Ct. 161].) And before the enactment of the ALRA, California corts also acknowledged that “so long as it can be argued that trespasoy union activity is protected under section 7 [of the NLRA], it s initially within the exclusive competence of the Board to reconcileTese section 7 rights with private property rights; state court jurisdictjn is displaced.” (Sears, Roebuck & Co. v. San Diego County Dist., Council of Carpenters (1976) 17 Cal.3d 893, 899 [132 Cal.Rptr. 43, 553 P.2d 603]; italics added.) Once ALRA was enacted, Califoria courts quickly acknowledged its foundational relationship and sinlarity to NLRA and California’s willingness to follow federal precdent in its interpretation. (See Kaplan’s Fruit & Produce Co. v. Suprior Court (1979) 26 Cal.3d 60, 67-*7171 [162 Cal.Rptr. 745, 603 P.2d 1341]; Belridge Farms v. Agricultural Labor Relations Bd., supra, 21 Cal.3d at p. 558.)
It is also well established in California that “there is no exception permitting state courts to exercise jurisdiction over peaceful labor activity merely because it involves trespass on private property.” (Sears, Roebuck & Co. v. San Diego County Dist., Council of Carpenters, supra, 17 Cal.3d at pp. 896-897.)
In 1981, the California Supreme Court reiterated, the rule that “.. . trespass statutes do not apply to lawful union activity.” (In re Catalano (1981) 29 Cal.3d 1, 11 [171 Cal.Rptr. 667, 623 P.2d 228].) In that case, the Supreme Court issued writs of habeas corpus directing that defendants be discharged from custody, where they had been arrested and convicted of trespassing after entering a construction site to inspect safety conditions and refusing to leave at the property owner’s request. The court concluded: “Thus the case coalesces into a simple but important ruling. That holding emanates from the decisions of this court and from the statutory recognition of that principle by the Legislature: a labor union representative who enters upon a jobsite to engage in lawful union activity does not illegally trespass upon the land. If, however, he does not confine himself to such lawful union activity he forfeits such protection and subjects himself to liability.” (Id., at p. 17.)
Applying the foregoing principles and rules to the instant case, the declaration of respondents’ counsel, although contradicted by the employer’s declarations, states that respondents entered onto the employer’s land for the purpose of communicating with nonstriking workers about a labor dispute. That lawful activity would, of course, not amount to illegal trespass.
It is argued on behalf of the board, however, as amicus curiae, and accepted by the author of the dissenting opinion herein, that the municipal court complaint, by alleging criminal activity, conferred on the court jurisdiction to try the criminal actions. We disagree.
The superior court was compelled to determine whether the respondents’ activities were arguably protected by the act. The evidence before the court on that issue went beyond the allegations of the criminal complaint and consisted of three declarations by the crew supervisor, one of which constituted the basis for the criminal complaint and each of which differed materially from the others, and a declaration by counsel *72for respondents which averred that the parties were engaged in an ongoing labor dispute, and that they entered the fields to conduct lawful labor-related activity. Faced with such evidence, the superior court in issuing the writ must have concluded that it could “fairly be assumed” that the actions of respondents were protected by the act, that is, arguably protected activity. (San Diego Unions v. Garmon, supra, 359 U.S. at p. 245 [3 L.Ed.2d at p. 783].)
In Musicians Union, Local No. 6 v. Superior Court (1968) 69 Cal.2d 695 [73 Cal.Rptr. 201, 447 P.2d 313], an injunction was issued by the court, based upon a complaint which alleged that picketing and mass demonstrations were being conducted for the purpose of coercing employers and other employees. The Supreme Court concluded that the trial court was without jurisdiction to issue the injunction. The determination of petitioners’ purpose was for the board, not the court; petitioners’ purpose was “arguably” to engage in protected activity, and therefore “respondent was without jurisdiction to enjoin the activities in question.” (Id., at p. 710.)
The dissent seems to take the position that, whenever a prosecuting attorney elects to file a criminal charge, the jurisdiction of the board is automatically eliminated. That position undercuts what we regard as the purpose of the ALRA. The history of labor disputes during the early part of this century shows a constant imposition on the judicial system of disputes over the conduct of the parties to such disputes. Suits for injunction and criminal prosecutions were the weapons used to resolve the disputes. Ultimately, first by the NLRA and, later, in California, by the ALRA, there were created administrative tribunals having a special expertise in not only labor law in its strict sense but in the actual conduct of labor disputes. The theory of those statutes was, so far as possible, to relieve the judicial system of the burden of refereeing labor disputes.
The issuance of the instant writ furthers the legislative (and congressional) preference for the resolution of labor disputes by one expert body, rather than the courts. (United Farm Workers v. Superior Court (1977) 72 Cal.App.3d 268, 272 [140 Cal.Rptr. 87].) As the United States Supreme Court stated in Garner v. Teamsters Union (1935) 346 U.S. 485, 490-491 [98 L.Ed. 228, 239, 74 S.Ct. 161]: “Congress did not merely lay down a substantive rule of law to be enforced by any tribunal competent to apply law generally to the parties. It went on to confide primary interpretation and application of its rules to a specific *73and specially constituted tribunal .... Congress evidently considered that centralized administration of specially designed procedures was necessary to obtain uniform application of its substantive rules and to avoid these diversities and conflicts likely to result from a variety of local procedures and attitudes toward labor controversies.”
The trial court did not err in issuing a writ of prohibition against the further exercise of municipal court jurisdiction in this matter. Where it is apparent that conduct arguably falls within the protection of the act, the doctrine of preemption deprives the state of jurisdiction. (Kaplan’s Fruit & Produce Co. v. Superior Court, supra, 26 Cal.3d at p. 70.)
The judgment is affirmed.
Kingsley, J., concurred.